1. Field of the Invention
The present invention relates generally to structural supports for use in refrigerator cabinets employing polyurethane foam insulation and, more particularly, to supports which may be used for supporting a pull out drawer that closes an open front of a refrigerator.
2. Description of the Prior Art
In the art of refrigerator cabinet construction, particularly where plastic inner liners are employed, it is frequently necessary to provide selective reinforcement because the plastic liner walls are not strong enough to carry shelf load even when the walls are foamed in place. For example, where shelf supports or the like are attached to the inner liner, particularly a plastic inner liner, some form of support is needed. A screw receiving aperture in the plastic is generally unsatisfactory, except where extremely light loads are involved, because insufficient area for thread engagement results and the entire load is concentrated on a very small portion of the plastic material. These factors contribute to premature undesirable deformation or cracking of the plastic sheet.
In a typical refrigerator construction, metallic plates are used generally as stiffening members where needed. In a more specific application, where a load such as a shelf is to be applied to a plastic inner liner, metallic or plastic back plates are employed.
Another type of local stiffener support is disclosed in U.S. Pat. Nos. 4,190,305 issued Feb. 26, 1980 and 4,107,833 issued Aug. 22, 1978 to Knight et al. These patents teach the use of a fibrous material behind the inner wall of the refrigerator cabinet to locally reinforce the cabinet. The material is compatible with polyurethane foam insulation.
Where exceptionally heavy loads must be applied to the inner liner, a separate metallic or molded plastic member may be employed which actually bridges between the inner liner and the outer case to transmit the applied interior load directly to the metal outer case. However, such members may act as a thermal conductor between the inner liner and outer wall.
The structural reinforcement is typically a localized reinforcement and does not extend beyond the localized areas to be reinforced. Hence, for heavily loaded pull out drawers utilized in bottom mount refrigerators such local structural reinforcement is not usually sufficient for a refrigerator having a plastic liner. There is a need for reinforcement beyond localized reinforcement.
The present invention relates to a refrigerator appliance having a pull out drawer or door mounted by guide rails to a refrigerator cabinet for closing an open front portion of the refrigerator cabinet. The refrigerator has a closed loop reinforcing assembly that maintains the structural integrity of the cabinet and drawer for loads carried by the guide rails. The closed reinforcing assembly includes a cabinet liner reinforcement assembly mounted within the refrigerator cabinet that co-operates with a drawer reinforcing brace assembly mounted within the refrigerator drawer.
The reinforcing bracket assembly is located within the cavity of the insulated cabinet and has side reinforcing portions extending along the liner side walls adjacent a corresponding one of the guide rails. The side reinforcing portions are mounted to both the cabinet liner side wall and the guide rails by fasteners passing through the guide rails and liner side walls. The side reinforcing portions are local reinforcement to the liner side walls adjacent the guide rails. The reinforcing bracket assembly, additionally has a rear wall arm extending orthogonal from the respective side reinforcing portions adjacent to and, preferably in contact with, an inside surface of the rear wall of the interior liner. The rear wall arm interconnects and reinforces the side reinforcing portions to structurally support the liner side walls of the liner from flexing outwardly from each other adjacent the guide rails. The interconnection of the side reinforcing portions by the rear wall arm structural liner and cabinet reinforcement beyond local reinforcement.
The reinforcing brace of the closed reinforcing assembly is secured within the drawer at least partially extending across the width of the drawer. The reinforcing brace is connected to the guide rails at end portions thereof to complete a closed reinforcing structure extending around the cabinet liner and across the drawer liner. In addition to providing local support, the closed reinforcing assembly or structure provides a box-like reinforcement able to support loads carried by the guide rails in addition to the load of the drawer.
The reinforcing bracket assembly provides local reinforcement of the liner side walls of the cabinet to support the guide rails mounted thereto. The reinforcement is further enhanced by the reinforcing bracket assembly when it is foamed in place. Additionally, the interconnection of the side reinforcing portions by the rear wall arm structurally supports the liner side walls from flexing inwardly and outwardly and prevents the transfer of stresses related to the opening of the drawer under predetermined load conditions which stresses would otherwise lead to the liner cracking.
In accordance with one aspect of the present invention, the reinforcing bracket assembly is located within the cavity of the refrigerator cabinet and has side reinforcing portions extending along the liner side walls adjacent a corresponding one of the guide rails. The side reinforcing portions are mounted to the liner side wall by fasteners passing through the guide rails and liner side walls. The side reinforcing portions having support flanges extending into and engaging the foam for providing local reinforcement to the liner side walls. The reinforcing bracket assembly has a rear wall arm extending orthogonal from the respective side reinforcing portions adjacent to and, preferably in contact with, the rear wall of the interior liner. The rear wall arm interconnects and reinforces the side reinforcing portions to structurally support the liner side walls of the liner from flexing relative to each other and to thereby prevent stresses from being transferred onto the liner from the pull out drawer when the pull out drawer carries a predetermined load into an open position.
The reinforcing brace of the refrigerator pull out drawer provides localized reinforcement to the drawer in addition to its role in the closed reinforcing assembly. In accordance with one aspect of the invention, the reinforcing brace is secured within the drawer and extends at least partially across the width of the drawer. The brace has two spaced apart members and a cross member connected to and extending between the wing members adjacent an inside surface of the inner liner of the drawer. Each of the wing members has a forward central portion and recessed opposing wing end portions extending from the forward central portion and secured within the drawer. One of the cross member and the forward central portion has an outward facing surface positioned across a corresponding one of spaced apart mounting support apertures located in the inner liner of the drawer. The wing members and the cross member are adapted for securement with a corresponding drawer mounting bracket at the outward facing surface.